1. Field of the Invention
This invention relates to a method of and apparatus for bending or straightening a material having both elastic and plastic characteristics. The method and apparatus are particularly suitable for use in straightening rail but can be used in other applications.
2. Description of the Prior Art
Downwardly-directed deflections or bends in rails forming part of railway line can arise for example through imperfect finishing of welds with a high volume of traffic over the rail. To give a smooth ride for a train over the rail, the rail requires straightening in situ, and such straightening is typically carried out using a three-point rail straightening apparatus having two spaced contact points on the rail and a rail lifting member between these points, the rail lifting member being arranged to lift a bar inserted beneath the rail. A disadvantage of this arrangement is that it is necessary to clear away ballast from beneath the rail before the bar can be inserted, and the ballast must be restored after the rail has been straightened. This adds to the time taken for each straightening operation.